Gear grinding machine



Jam 15, 1942;.

l. J. GRUENBERG ET AL GER GRINDING MACHINE Filed Jan. 24, 1944 2Sheets-Sheet 1 ATIORNEY Jan. l5, 1946,

' l. J. GRUENBERG ET Al.

GEAR GRINDING MACHINE F'iled'Jan. 24, 1944 2 sheets-'sheet 2 INVENTORS IVOR J.GRUENBERG SAMUEL G.BRADY ATTORNEYS Patented Jan. l5, 1946 GEARGRINDING MACHINE Ivor J. Gruenberg, Pleasant Ridge, and Samuel G. Brady,Royal Oak, Mich., assignors to The Gear Grinding Company, Hamtramck,Mich., a

corporation of Michigan Application January 24, 1944, Serial No. 519,492

3 Claims.

The invention relates to gear grinding machines of that type in whichthe gear is ground by a formed grinder wheel, the latter being trimmedto a cross sectional contour corresponding to the interdental contour ofthe nished work.

It is the object of the invention to adapt a grinding machine of thistype to the grinding of gear teeth' which are non-rectilinear in anaxial plane. For instance, in one form of gearing the engagement betweenconjugate gears when relieved from load is only in the central portionof the length of the gear teeth. Thus, at any deflection or deformationofthe gear teeth due to load will be in the center and not at Vthe ends.With machines ofthe type above referred to the movement of the workrelative to the grinder wheel is rectilinear and, consequently, theteeth are necessarily of the same contour and .radial dimension in allportions of the length thereof. However, by means of our improvementthis condition is altered. 'Ihe invention, therefore, consists in themeans for varying the distance between the axes of the work and grinderwheel during the relative axial movement thereof.

'Ihe invention further consists in the means for maintaining a xedrelation between the axis of the grinder wheel and the trimmingmechanism during the periodic retrimming operations.

Still further the invention consists in the peculiar construction andarrangement of parts as hereinafter set forth.

In the drawings:

Fig. l is a side elevation of a gear grinding machine to which ourimprovements are applied; and

Fig; 2 is an end elevation thereof.

In general construction our improved grinding machine comprises a baseor bed A having guideways B thereon rfor a travelling work carryingtable C. At one side of this table is a column D rising from the bed,said column having vertical guideways E for an adjustable cross head Fon which the grinder wheel is mounted, the parts thus far describedbeing similar to constructions heretofore used.

Instead of mounting the grinder wheel and its supporting arbor in xedbearings on the cross head F, these parts are mounted on an oscillatoryframe G fulcrumed on said head. As shown, H is a shaft extendingtransversely through supporting bearings in the head F to extend onopposite sides of said head. I are antifriction ball or roller bearingsmounted on the opposite ends of the shaft H and engaging seats inbifurcated arms G' of the frame G. J is the arbor for the grinder wheelwhich is journaled in bearings J to extend parallel to but spaced fromthe shaft H. At one end of this arbor is the driving motor J2 whileatthe opposite end is mounted the grinder wheel J3 arranged above thetable C. The gear to be ground, such as K,

lis mounted on centers on the table C to have its axis extend parallelto the guideways B and is also connected with a suitable indexingmechanism. However, as these parts are of conventional l constructionillustration of the same is omitted in the drawings.

Mounted on the table C at one side thereof is a bar L on which isadjustably secured a cam member L'. M is a cam follower roll at thelower end of a rodM depending from. the frame G. The parts are soarranged that during the longitudinal movement of the tableV C through adistance equal to orgreater than the axial length of the gear teeth thecam follower roll M will ride over the' cam L' so as to raise and lowerthe oscillatory frame G and the grinder wheel J carried thereby. Thus,the path of the grinder wheel with respect to the work is curved in anaxial plane and this curvature is determined by the shape of the cam L.

It is customary in grinding machines of the type to mount a trimmingmechanism on the work holding table so that by moving this table beyondits work grinding position the trimming mechanism may be registered withthe grinder wheel after which the trimming may be accomplished in theusual manner. Inasmuch, however, as the grinder wheel is movedvertically during oscillations of the frame G, it is necessary to holdthis frame in a predetermined fixed position while it is in registrationwith the trim- ,ming mechanism. This is accomplished by a second cammember L2 mounted on the bar L and spaced from the cam L a distanceequal to the distance between the grinding and trimming positions of thework table. One end of the cam L2 is curved or inclined to facilitatethe mounting thereupon of the follower wheel M, while beyond this curvedportion is a portion for holding the grinder wheel in its trimmingposition.

It is necessary to provide the machine with adjustments so as toaccommodate the same to gear wheels of different diameters, and it isfurther necessary to make adjustments as the grinder wheel isperiodically retrimmed and thus changed in radius. A screw N extendingupward from the cross head F and cooperating with a nut (not shown)operated by a hand wheel N at the top o! the column D forms the meansfor vertically adjusting said cross head, this being the conventionalmeans for moving the grinder wheel toward or away from the work in geargrinding machines. There is also a screw O mounted in the frameG andhaving a swivel connection with a rod M to extend upward in alignmenttherewith. This screw engages a nut mounted on their-ame G and at theupper .end of the screw is an operating crank handle On by which it maybe revolved. A graduated sleeve O3 telescopically engaging a housing O*surrounding the screw indicates the. amount of rotative adjustment and aclamping screw O5 detachably connects this sleeve with the screw O.Thus, the sleeve may vbe moved to aero position and the amount ofrotative adjustment of the screw thereafter accurately indicated.

-To limit the amount of of the frame G, the head F is provided with aforwardly extending arm F' having a button li*n thereon in alignmentwith a buttoni on said trame G. Thus, when the cam follower M disengages from the cam L' the cooperating buttons Fl and F will limit thedrop of the frame.A

In operation, the amount of axial curvature in the teeth of the gearbeing determined, a suitably proportioned cam L is mounted on the bar L.By means of an adjustable slide L3 on said bar andan adjusting screw L4between the slide and cam, the latter may be accurately addownward'oscillation Justed in position to correspond to the position of thework. The cam L -is also mounted and properly positionedv on the bar L.The grinder wheel is fashioned to the proper contour by moving the tableC so as to anism P mounted on said table with the grinder wheel J3. Inthis position the ca'm Lz will hold the oscillatory frame G in apredetermined fixed position where the trimming is to be performed. Suchposition may. however, .be changed to compensate for wearV in the wheelby an adjustment of the screw O. After the grinder wheel is properlyfashioned, the table is moved to its working position and isreciprocated through a length of movement corresponding to the length ofthe gear teeth. At the opposite ends of this movement the grinder wheelwill be depressed but as it rides over the center of the cam L' it willbe raised to its highest position. This will impart to the gear thedesired longitudinal contour to the teeth.

register a trimming mechl What we claim as-our invention is:

l. In a grinding machine, the combination with a reciprocatory workcarrying table, a mounting for a gear to be ground thereon and a formedgrinder wheelof a laterally extending oscillatory frame above said tableon which said grinder wheel is mounted, a bar mounted on said work tableto extend parallel thereto, a cam on said bar, a cam follower dependingfrom said oscillatory frame engaging said cam to raise and lower thegrinder wheel during the axial movement of the work relative thereto,and asecond cam on said bar, the latter being adapted to position saidoscillatory frame and grinder wheel for the trimming of the latter. f

2. In a grinding machine, the combination with a reciprocatory workcarrying table, a mounting for a gear to be ground thereon and a formedgrinder wheel of a stationary column, a head verticallyyadjustablymounted on said column,

an oscillatory frame pivotallymounted on said head and extendinglaterally therefrom, having a mounting for said grinder wheelintermediate its ends, a bar mounted on said work carrying table, a camadjustably mounted on said bar, a cam follower depending from the freeend of said oscillatory frame and engaging said cam to raise and lowerthe grinder wheel during the axial movement of the work relative theretoand cooperating members on said head and oscillatory frame for limitingthe downward movement of the latter when said follower is disengagedfrom said cam.

3. In a grinding machine, the combination with a reciprocatory workcarrying table, a mounting for a gear to be ground thereon and a formedgrinder wheel of a laterally extending oscillatory -frame above saidtable on which said grinder wheel is mounted, a cam mounted on said worktable, a pivotal support for said oscillatory frame -at one end thereof,a cam follower depending from the opposite end of said oscillatory frameengaging said cam to raise and lower the grinder 'wheel during the axialmovement of the work relative thereto, a screw for adjusting saidfollower relative to said oscillatoryframe and extending upward abovethe latter, a handle for rotating said screw, and an indicator for therotation of said screw determining the amount of adiustmentof saidfollower.

IVOR J. GRUENBERG. SAMUEL G. BRADY.

